According to Fundstrat head of research Thomas Lee, the recent decline in Bitcoin (BTC) price is likely the result of the expiration of Bitcoin futures, Bloomberg reports June 14.

In a report, Lee explained that the “gut wrenching” weakness in Bitcoin (BTC), which dropped upwards of 20 percent earlier this week, was the result of futures contracts expiring. Lee said the “significant volatility” is one of six expirations of Bitcoin that have happened since CBOE launched its futures contracts in December 2017. Lee wrote:

“Bitcoin sees dramatic price changes around CBOE futures expirations… We compiled some of the data and this indeed seems to be true.”

According to Lee, Bitcoin usually sees a drop of around 18 percent in 10 days before futures expiration, with prices generally recovering by six days afterward. Lee explained that if a trader is long on Bitcoin and short the futures, holders may sell large shares of BTC at the volume weighted average price as contracts move closer to expiring.

Near expiration however, they may sell the remaining Bitcoin, which causes the price to drop, and leaving the short position in the futures they close “with a handsome profit.”

Lee also noted a low amount of investment in crypto markets this year, claiming that there’s more net supply this year amid initial coin offerings (ICOs), mining rewards, and capital gains taxes.

Crypto markets saw a slight rebound today, seeing gains of total market cap of around $20 bln from Wednesday’s low of $271 bln. Having dropped as low as $6,263 this week, Bitcoin has seen a growth of over 5 percent in the 24-hour period, and is trading around $6,618 at press time.

Recently, Cointelegraph reported that US Commodity Futures Trading Commission (CFTC) has launched a probe into four major crypto exchanges Bitstamp, Coinbase, itBit, and Kraken that have been providing data for CME Group, which launched Bitcoin futures trading in December 2017. The CFTC is investigating whether these platforms have taken any action that could constitute manipulation of cryptocurrencies’ prices.